tool · ops / scheduling

@v0idd0/cronwtf.

translate cron expressions into plain english.

paste any cron string. get the human-readable version + the next 5 fire times in your timezone. supports the standard 5-field syntax + jenkins / quartz extensions.

npm i -g @v0idd0/cronwtf

github → npm mit · free forever

0 9 * * *→every day at 09:00

*/15 * * * *→every 15 minutes

0 0 1 * *→first day of each month, midnight

30 18 * * 5→fridays at 18:30

0 */4 * * *→every 4 hours, on the hour

0 9 * * 1-5→weekdays at 09:00

@hourly→alias: top of every hour

H/10 * * * *→jenkins: every 10min, randomized

0 9 * * *→every day at 09:00

*/15 * * * *→every 15 minutes

0 0 1 * *→first day of each month, midnight

30 18 * * 5→fridays at 18:30

0 */4 * * *→every 4 hours, on the hour

0 9 * * 1-5→weekdays at 09:00

@hourly→alias: top of every hour

H/10 * * * *→jenkins: every 10min, randomized

what it does

no more squinting at /15 9-17 * 1-5 means.

four jobs. all in your terminal. no api call, no internet round-trip — just a plain tool that does what it says.

explain a string

$ cronwtf '*/15 9-17 * * 1-5'

every 15 min
between 09:00–17:00
monday → friday

next fire times

$ cronwtf --next 5 '0 */6 * * *'

2026-04-29 00:00
2026-04-29 06:00
2026-04-29 12:00
...(+2 more)

compare two crons

$ cronwtf diff '0 9 * * *' '0 9 * * 1-5'

+ runs weekends
- skips weekends

check syntax flavor

$ cronwtf check 'H 4 * * *'

valid · jenkins-only
fails on unix cron

install

three ways. all painless.

npm

$ npm i -g @v0idd0/cronwtf

node 14+ on linux / macos / windows. updates with npm update -g.

github releases

$ curl -L github.com/voidd0/cronwtf/releases/latest

single static binary. zero runtime needed. all releases →

git clone

$ git clone github.com/voidd0/cronwtf

read the source, send a pr, fork it. mit licence, no cla. repo →

why we built it

we kept asking each other “does 0 0 * * 0 mean monday or sunday?” — and getting different answers. so we wrote a parser that just tells you in english.

no telemetry. no signup. no “upgrade for the next-fire-time feature.” mit forever — the source is public and the npm package is yours to fork.

star on github → all tools

comparing tools? voiddo cronwtf vs crontab.guru →

power user?

use this daily? tools.voiddo Pro · $9 one-time

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